Aedes (Stegomyia) hogsbackensis, Yiau-Min Huang, 2004

Yiau-Min Huang, 2004, The subgenus Stegomyia of Aedes in the Afrotropical Region with keys to the species (Diptera: Culicidae), Zootaxa 700, pp. 1-120 : 43-47

Aedes (Stegomyia) hogsbackensis New Species

( Figs. 18 C; 19B,D,E; 24C6,D5; 39A; 50B,C) Aedes (Stegomyia) poweri (Theobald) , Muspratt 1953: 83 (M*, F*, L; in part); Muspratt 1956: 72 (M, F*, L) (in part).

FEMALE. Head. Proboscis dark­scaled, without pale scales on ventral surface, longer than forefemur; maxillary palpus about 0.20 length of proboscis, dark, with white scales on entire dorsal surface of palpomere 3; pedicel covered with white scales except on dorsal and ventral surfaces; antenna with a few dark scales on flagellomere 1; clypeus bare; occiput with few erect forked scales; a row of broad white scales around eye margins; vertex with a median stripe of broad white scales, with broad dark scales on each side interrupted by lateral stripe of broad white scales, followed ventrally by a patch of broad white scales. Thorax. Scutum with narrow dark scales, and a distinct median white spot of broad scales on anterior promontory, followed by a narrow median longitudinal stripe of narrow yellowish scales, reaching to prescutellar area; prescutellar line of narrow yellowish scales not present, with only a few narrow yellowish scales; (Drakensberg specimens prescutellar line of narrow yellowish scales usually present, sometimes with only a few narrow yellowish scales, or sometimes absent); fossal area with a large patch of broader crescent­shaped white scales; posterior dorsocentral white line of narrow scales present, reaching to posterior 0.4 of scutum; a patch of narrow white scales on lateral margin just in front of wing root; acrostichal setae absent; dorsocentral setae present; scutellum with broad white scales on all lobes and with a few broad dark scales at apex of midlobe; antepronotum with broad white scales; postpronotum with a small patch of broad white scales and a few dark narrow scales dorsally; paratergite with broad white scales; postspiracular area without scales; hypostigmal area without scales; subspiracular area without scales; patches of broad white scales on propleuron, upper and lower portions of mesokatepisternum, and on mesepimeron; upper mesokatepisternal scale patch not reaching to anterior corner of mesokatepisternum; upper mesepimeral scale patch connecting with lower mesepimeral scale patch; lower mesepimeron without setae; metameron without broad white scales; mesopostnotum bare. Wing. With dark scales on all veins except for a minute basal spot of white scales on costa; cell R2 2.8 length of vein R2+3. Halter . With dark and white scales. Legs ( Figs. 19 B,D; 24C6). Coxae with patches of white scales; white knee­spot absent on forefemur, present on mid­ and hindfemora; forefemur anteriorly with a narrow, white longitudinal stripe on ventral surface in basal 0.36; midfemur with a large, white spot on anterior surface about 0.55 from base; midfemur with some pale scales scattered on anterior surface in basal 0.50; hindfemur anteriorly with a broad, white longitudinal stripe in basal 0.56 that widens 0.14 from base; foretibia anteriorly dark with a basal white band; midtibia anteriorly dark, with a distinct white longitudinal stripe on ventral surface in basal 0.12; hindtibia anteriorly with a white longitudinal stripe on ventral surface in basal 0.22; foretarsomere 1 with basal 0.12 white on dorsal surface; foretarsomere 2 with basal 0.23 white on dorsal surface; midtarsomere 1 with basal 0.29 white on dorsal surface; midtarsomere 2 with basal 0.55 white on dorsal surface; hindtarsus with a basal white band on tarsomeres 1–3, the ratio of length of white band on dorsal surface to the total length of tarsomere is 0.24, 0.32 and 0.26; hindtarsomere 4 all white except at extreme apex; hindtarsomere 5 all dark; fore­ and midlegs with tarsal claws equal, all toothed; hindleg with tarsal claws equal, both simple. Abdomen. Tergum I with white scales on laterotergite; terga II–VII each with a basal white band and basolateral white spots which do not connect with the basal white band; sterna III–VII each with a basal white band; segment VIII largely retracted.

MALE. Essentially as in the female, differing in the following sexual characters: Head. Maxillary palpus slightly shorter than proboscis, predominantly dark, with a white band at base of palpomeres 2–5, those on palpomeres 4,5 dorsally incomplete; palpomeres 4,5 subequal, slender, dorsally curved and with only a few short setae; antenna plumose, shorter than proboscis. Thorax. (Drakensberg specimens subspiracular area with broad white scales). Wing. Cell R2 about 3.0–0.33 length of vein R2+3. Legs ( Figs. 18 C; 19E; 24D5). hindfemur anteriorly with a broad white longitudinal stripe in basal 0.57–0.60 that widens 0.1–0.2 from base; midtibia anteriorly dark, with a distinct white longitudinal stripe on ventral surface in basal 0.12–0.14; hindtibia anteriorly with a white longitudinal stripe on ventral surface in basal 0.23–0.36; foretarsomere 1 with basal 0.13–0.14 white on dorsal surface; foretarsomere 2 all dark, or with only a few white scales on dorsal surface in basal area; midtarsomere 1 with basal 0.23–0.24 white on dorsal surface; midtarsomere 2 with basal 0.30–0.35 white on dorsal surface; hindtarsus with a basal white band on tarsomeres 1–3, the ratio of length of white band on dorsal surface to the total length of tarsomere is 0.25–0.27, 0.22–0.27 and 0.16–0.18; fore­ and midlegs with tarsal claws unequal, the smaller one toothed, the larger one simple. Abdomen. Sternum VIII with basolateral white spots. Genitalia ( Fig. 39 A). Gonocoxite 2.2 times as long as wide (width measured 0.5 from base); claspette large, lobed, distal expanded portion oval in dorsal aspect, with numerous simple setae on the expanded distal portion and bearing 3 stronger, basally widened setae on the apicomesal corner; gonostylus simple, elongate, 0.54–0.56 length of gonocoxite, with a long slender claw process at apex; paraproct with a sternal arm; cercal setae absent; apical margin of tergum IX slightly concave medially with 8–11 setae on each lateral lobe; sternum IX without setae.

PUPA. Essentially as in Ae. ledgeri ( Huang 1981, Fig. 5 ), with the following diagnostic characters: Abdomen. Seta 3­II,III usually single (1–2) and barbed, shorter than segment III; 5­IV­VI usually single (1–2) and barbed, not extended beyond posterior margin of following segment; 9­I­VI small, single, simple; 9­VII usually single (1–2) and barbed, 9­VII,VIII much longer and stouter than 9­I­VI; 9­VIII usually with 4 branches (2–4) and barbed. Paddle ( Fig. 50 B). Oval, about 1.25 times as long as wide; margins with distinct denticles, without fringe of long hair­like spicules; apex notched. Male genital lobe short and broad, much shorter than wide.

LARVA. Essentially as in Ae. ledgeri ( Huang 1981, Fig. 6 ), with the following diagnostic characters: Head. Seta 1­A single, simple. Thorax. Basal spine of meso­ and metapleural setae groups long, stout, apically pointed. Abdomen. Seta 1­VIII usually with 4 branches (3–4), barbed; 3­VIII usually with 5 branches (5–6), barbed; 5­VIII usually with 5 branches (4–5), barbed; comb usually with 6 (6–10) scales in a row, each scale with free portion widened at base and sharply pointed at apex, and with fine denticles at base; saddle incomplete, marginal spicules very small and inconspicuous; seta 1­X with 2 branches, barbed; 2­X usually with 3 branches, rarely 2­branched; 3­X single; 4­X with 4 pairs of setae on grid, each seta 2­branched; no precratal tufts; anal papillae about 4.5–5.0 length of saddle, sausage­like. Siphon. about 1.4 times as long as wide 0.5 from base, acus absent; with usually 11 (8–12) pecten spines, evenly spaced, each spine with basal denticles, 2–5 denticles on the ventral side, and 1–3 smaller denticles on the dorsal side; seta 1­S usually with 4 branches (3–4), barbed, inserted beyond apical spine and beyond middle of siphon.

TYPE DATA. Holotype male (MEP Acc. 806/ South Africa 1980, #66­11, Y. M. Huang), with associated larval and pupal skins on slide, with genitalia on slide (81/52), Hogsback (32° 36' S, 27° 01'E), Cape Province, SOUTH AFRICA, collected as larva from a medium size stump hole, about 0.2 m above ground, in a plantation, 7­III­1980 (Y.M. Huang). Deposited in the Smithsonian Institution, Washington, D.C. [ USNM]. Allotype female (MEP Acc. 806, #66­13), with associated larval and pupal skins on slide, with genitalia on slide (81/53), same data as holotype [ USNM]. Paratypes: 3 males: 1 male (MEP Acc. 806, #66­10), with associated larval and pupal skins on slide, same data as holotype [ USNM]; 2 males (MEP Acc. 806, #65­10, ­11), with associated larval and pupal skins on slides, with genitalia on slides (81/50, 81/51), collected as larvae from a small stump hole, 7­III­1980 (Y.M. Huang), same data as holotype [ USNM].

OTHER MATERIAL EXAMINED. SOUTH AFRICA. Cape Province: Kologha Forest (32° 30' S, 27° 20' E), 1952, J. Muspratt, 1M ( SAIMR, CSIR­ 52, Coll. No. A381E/ Aedes (S.) poweri Theo. Det. J.M. 1952 ) [ BMNH]; same data, 2M, 1F ( SAIMR /YF/ CSIR­ 52, Coll. No. A379E, A382/E1, A379/E/ Aedes (S.) poweri Theo. Det. J.M. 1952 ), 2 M gen, 1 F gen (MEP Acc. 719, 81/42, 81/43, 81/41) [ BMNH]; same data, 3M ( SAIMR, CSIR­ 52, Coll. No. A382E/ Aedes (Steg.) poweri Theo. Det. J.M. 1952 ), 2 M gen (MEP Acc. 724, 81/44, 81/45) [ ORSTOM]. Natal, Drakensberg (29° S, 29° E), 1978, J. Muspratt, 5M, 3F (0000/78/­, 6, ­7, ­8, ­9, ­1, ­2, ­3/ Aedes (Steg.) poweri (Theo.) Det. J.M. 1952 ), 3 M gen, 1 F gen (MEP Acc. 699, 81/47, 81/48, 81/49, 81/46) [ USNM].

DISTRIBUTION. This species is known only from South Africa.

TAXONOMIC DISCUSSION. Aedes hogsbackensis , a member of the poweri group, has the scutum with an anteromedial white spot of broad scales, midtibia with a white stripe on ventral surface in basal area, hindtibia with a white stripe on ventral surface in basal area and hindtarsomere 5 all dark, and can thus be easily distinguished from all other species of the poweri group except Ae. poweri .

Aedes hogsbackensis is extremely similar to that of Ae. poweri with which it has been confused and misidentified, but can be distinguished from Ae. poweri by: (1) the female midtarsomere 2 with basal 0.55 white on dorsal surface; and (2) the male midtarsomere 2 with basal 0.30–0.35 white on dorsal surface. In Ae. poweri , the female midtarsomere 2 has basal 0.9 white to all white on dorsal surface, and the male of Ae. poweri is not known.

The adult male and female of Ae. hogsbackensis are also very similar to those of Ae. contiguus Edwards , but can be distinguished from those of Ae. contiguus by the midtibia with a white stripe on ventral surface in basal area. In Ae. contiguus , the midtibia has no white stripe on ventral surface in basal area.

The male genitalia of Ae. hogsbackensis are differentiated from all other species in the poweri group by the claspette, which has the distal expanded portion oval in dorsal aspect, with numerous simple setae on the expanded distal portion and bearing 3 stronger, basally widened setae on the apicomesal corner, and by the apical margin of tergum IX, which is slightly concave medially and has well separated lateral lobe, each with 8–11 setae.

The male genitalia of Ae. hogsbackensis are very similar to those of Ae. contiguus in having the claspette with distal expanded portion oval in dorsal aspect, but can be distinguished from those of Ae. contiguus by the apical margin of tergum IX with well separated lateral lobe, each with 8–11 setae. In Ae. contiguus , the apical margin of tergum IX has slightly separated lateral lobe (very narrow space between them), each with 12–14 strong setae.

Aedes hogsbackensis is apparently a montane forest species that occurs in habitats with altitudes between 1,200 and 1,666 m in areas of yearly rainfall of 101.6–139.7 cm.

BIONOMICS. Larvae of Ae. hogsbackensis were collected from stump holes in Hogsback (type specimens), and from tree holes in Kologha Forest, Cape Province; and from a small tree hole in montane forest, near Drakensberg, Natal, South Africa.

Aedes hogsbackensis has been collected in association with Ae. aegypti from a medium size stump hole (MEP Acc. 806, #66), in Hogsback, Cape Province, South Africa.

Mattingly (1953: 30) reported that a number of females were taken biting man in the Kologha Forest ( Muspratt 1953). We now know that Musprattís Ae. poweri included two distinct species. The specimens from Kologha Forest, Cape Province that Muspratt (1953, 1956) included Ae. poweri as well as the new species Ae. hogsbackensis .

MEDICAL IMPORTANCE. Unknown.

Figures

FIGURE 5. Aedes (Stg.) unilineatus — A, thorax (dorsal view); C, head and proboscis (dorsal view); Aedes (Stg.) granti — B, head and proboscis (dorsal view); D, thorax (dorsal view).

FIGURE 6. Aedes (Stg.) unilineatus — A, female tarsal claws (fore­, mid­ and hindlegs); B, female fore­, mid­ and hindlegs (anterior view); C, male fore­, mid­ and hindlegs (anterior view); D, male tarsal claws (fore­, mid­ and hindlegs).

FIGURE 18. Aedes (Stg.) mpusiensis — A, male (Holotype) fore­, mid­ and hindlegs (anterior view); Aedes (Stg.) ethiopiensis — B, male (Holotype) fore­, mid­ and hindlegs (anterior view); Aedes (Stg.) hogsbackensis — C, male (Holotype) fore­, mid­ and hindlegs (anterior view).

FIGURE 19. Aedes (Stg.) poweri — A, thorax (dorsal view); C, female fore­, mid­ and hindlegs (anterior view); Aedes (Stg.) hogsbackensis — B, female fore­, mid­ and hindlegs (anterior view); D, female tarsal claws (fore­ and hindlegs); E, male tarsal claws (fore­ and hindlegs).

FIGURE 39. Aedes (Stg.) hogsbackensis — A, male genitalia; Aedes (Stg.) soleatus — B, male genitalia.

FIGURE 50. Aedes (Stg.) chemulpoensis — A, male genitalia. Aedes (Stg.) hogsbackensis — B, larva; C, pupa.